Companies such as Volkmann and Verdol have made yarn twisting machines for years.
In common configurations of two-for-one twisters, first a roll of yarn is placed in a pot and possibly fed through a tension device to a loading roll. A second yarn roll which is twisted about the first yarn is fed from a creel like structure normally at an elevated portion above the twister which proceeds downwardly and then around the pot. The second yarn is twisted about first yarn at an eyelet as it is fed to a loading roll. A tension device is also normally utilized on the second feed roll.
Many prior art twisters have a creel location for a third yarn roll near the second yarn roll. The third yarn roll is utilized to tie to the tail of the second yarn so that it can then proceed in an uninterrupted manner after the second roll of yarn expires during the twisting process.
Traditionally, the only variation that could be had during twisting would be to change the tensions either as applied to either the first or the second feed rolls or change the speed of the take up roll so as to potentially change the twist per inch.
By substituting the gearing, it might also be possible to change the speed of rotation of the second yarn about the first yarn through the use of a different gear.
Patents such as U.S. Pat. No. 5,706,642 show a variable twist level yarn which utilizes a controller to be able to change the twist rate on the fly of a traditional two-ply yarn construction. As one can see from that patent, there was no way to change tension.
U.S. Pat. No. 8,650,849 is a yarn feed device which employs ways of changing tension on the first and second yarns.
U.S. Pat. No. 8,256,199 also shows a method for operating a two-for-one twister.
U.S. Pat. No. 6,098,392 shows a rather interesting structure that provides for a way to feed multiple yarns as first and second yarns, respectively, but only in specified ways. In this construction yarns one and two are described as being co-twisted in a single direction to form a creel component yarn having an S or Z twist pattern. While it may be possible to get the technology of U.S. Pat. No. 6,098,392 to work on a certain situation, the applicant has tried some features shown in this patent without success.
However, improvements over all these prior arts technologies have been made by the applicant in an effort to provide relatively unique twist variations to the marketplace through various embodiments.